Friday 24 January 2014

The climate of intellect


It has been so hot that I have been unable to write anything about an interesting paper on the effects of climate on intelligence.

Climato-economic habitats support patterns of human needs, stresses, and freedoms
Evert Van de Vliert.


The paper runs to 15 pages, and with peer comentary it turns into a 57 page blockbuster, and I have no air-conditioning. The ceiling fans have an ominous tendency to wobble as they gain speed, suggesting that they are about to detach themselves from their fragile moorings, and spin their metal blades through anything they encounter on the way down, an alarming prospect if one is lying naked on the bed beneath. Instead I have been using a floor mounted fan, but that points lovingly at its cousin on the ceiling, and has little effect at bed level. I would attempt to adjust it, but it is too hot to try anything complicated.

It is only thanks to a momentary sea breeze I am able to bring you a brief summary. It appears to be a re-working (or a re-warming) of a familiar hypothesis, that winter sharpens the mind, because without careful planning you might starve before next harvest. Notice: you not only have to survive winter, you have to survive Spring and Summer as well. Not for nothing did the Saxons consider that the end of summer, just before harvest, was a time of great starvation. Failures led to death, and in Elizabethan times it was not unusual for isolated communities to die of famine. Winter keeps people on their toes.

“This core hypothesis is supported with new survey data across 85 countries and 15
Chinese provinces and with a reinterpretative review of results of prior studies comprising 174 countries and the 50 states in the United States. Empirical support covers freedom from want, freedom from fear, freedom of expression and participation, freedom from discrimination, and freedom to develop and realize one’s human potential. Applying the theory to projections of temperature and income for 104 countries by 2112 forecasts that (a) poor populations in Asia, perhaps except Afghans and Pakistanis, will move up the international ladder of freedom, (b) poor populations in Africa will lose, rather than gain, relative levels of freedom unless
climate protection and poverty reduction prevent this from happening, and (c) several rich populations will be challenged to defend current levels of freedom against worsening climato-economic livability.

As you can see, van der Vliert works in Norway, and in that culture people tend to be thorough, though prone to gloom brought on by sunless winters. Theirs is the only economy which is always in surplus, and their sovereign wealth fund makes them all millionaires. Winter has been kind to them, plus oil deposits under the North Sea. However, this is not a paper in the conventional sense, but a summary and overview of many previous studies which have been brought together for this issue. The detailed stuff is in technical appendices.

“Climato-economic theorizing similarly posits that the demands and the resources of the human habitat influence each other’s impact on the needs, stresses, and choices
shared by inhabitants. Greater climatic demands in interaction with poor monetary resources eventually promote avoiding ambiguity by making relatively unfree choices that are necessary and routine rather than autonomous and adventurous. Greater climatic demands in interaction with rich monetary resources eventually promote seeking ambiguity by making relatively free choices that are autonomous and adventurous rather than necessary and routine. This explanation of cultural management of ambiguity and free choice is presented here in subsections describing main effects of climatic demands, interactive effects of monetary resources, differential effects of cold and heat, and shared psychobehavioral adaptations.”

Heady stuff. How good is the argument? First of all, in terms of style the writing is content-rich. It is more than just a winter hypothesis, in that van der Vliert has categorized climates by their level of demand on human behaviour (both cold winters and very hot summers make life difficult, whereas 22 C is the Goldilocks mean) and has also differentiated between rich and poor countries. His focus is very much on human freedoms, which he sees as an outcome of the interplay between climate and resources.



Turning to methods, van der Vliert has put together a measure of climate demand which is more sensitive than simple temperature, and uses that as his climate variable (page 6). Naturally, this is based on modern climate data, whereas in evolutionary terms it would be interesting to estimate climate in earlier times, in so far as this can be done. Monetary resources are calculated in 2004 purchasing power parity dollars. That is OK, but begs the question as to how those countries got to be rich in the first place. The author does not appear to mention national intelligence or scholastic achievement measures, which is a significant omission. However, van der Vliert defends this approach in his reply to the peer commentary, saying that the addition of Lynn and Vanhanen’s IQ by country data did not make much of a difference:

“In a double check, IQ was added to each of the six prediction models in Table R2. In Model 1, national IQ predicted 46% of the variation in overall freedom (b = .04,
n = 71, p < .01), wiping out the initial impact of parasitic disease burden (b = −.11, p = .12). However, Models 2 to 6 then wiped out the initial impact of national IQ,
showing that neither intelligence nor parasitic disease burden mediates the interactive influences of heat demands, cold demands, and monetary resources on
overall freedom. In Model 6, national IQ (b = .01, p =.23), parasitic disease burden (b = .04, p = .55), heat demands (b = −.20, p < .05), cold demands (b = −.09, p
= .51), the interaction of heat and cold demands (b = .02, p = .88), monetary resources (b = .36, p < .01), the interaction of heat demands and monetary resources (b = −.04, p = .76), the interaction of cold demands and monetary resources (b = .50, p < .001), and the three-way interaction (b = −.10, p = .42), accounted for 75% of the variation in freedom from press repression, ingroup discrimination,
and political autocracy. In sum (and in response to Allik & Realo), there is not the slightest indication that Lynn and Vanhanen (2006) were right in assuming that national IQ drives governmental democratization.”

I think that this seems to come down to a battle of the statistical models used, but at least intelligence data are being included, even though conclusions like “not the slightest indication” cast the debate in a dramatic light.

“Accumulating evidence suggests that climatic demands are associated with degrees of fundamental freedom, but that these effects can be observed only if we distinguish
between poor and rich populations. Across studies, climatic demands (M = 5% always accounted for considerably less variation in freedom than both monetary resources (M =27%) and the climato-economic interaction term (M =13%). All in all, repression of freedom is most likely in poorer populations that had to adapt to threatening colderthan-temperate or hotter-than-temperate climates, intermediately
likely in poor or rich populations that had to adapt to comforting temperate climates, and least likely in richer populations that had to adapt to challenging colder-thantemperate or hotter-than-temperate climates. The strength that this conclusion is based on studies addressing different freedoms and using different samples and methods comes with the weakness that the results do not provide independent
evidence. Rather, the results concern slightly different manifestations of overall freedom, loosely patterned around the central themes of threat appraisals, comfort
appraisals, and challenge appraisals (for empirical evidence, see Electronic Supplement 3).

Electronic Supplements 1 through 6 are available at


In sum, this is a different take on the fascinating question of what makes some countries rich and poor, and some tough and other tender: climate.



  1. Oddly enough, temperature correlates very strongly (inversely) with IQ and other well-being variables just within the 50 U.S. states...

  2. Kudos for giving this paper a fair review.

    The key problem with theories that try to explain national wealth without using IQ is that it's as if these folks never heard of Occam's Razor: any alternative explanation is bound to be conceptually more complicated. It's not like they begin by positing why national IQ doesn't work as an explanation.

    And of course, it's not like these alternative explanations are as nice and neat as their proponents hope. There's a plethora of facts that only make sense when you consider IQ:

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  3. They say that not necessarily the higher the latitude the smarter the people but undeniably certain high latitude areas foster intelligence better than lower latitude areas. So if we notice, climate really affects the intelligence. People in the cold climate are innovative and fast thinkers in order to survive.